Material cooling apparatus



Feb. 2, 1965 -M. J. GREAVES ET AL 3,168,384

MATERIAL COOLING APPARATUS Filed Feb. 2, 1962 5 Sheets-Sheet 2 1NVENTOR5 M54 V/A/ J. 69:74 Vii 7'44: vii/Vi? Feb. 2, 1965 M. J. GREAVES ET AL MATERIAL COOLING APPARATUS 5 Sheets-Sheet 3 Filed Feb. 2, 1962 Feb. 2, 1965 J. GREAVES ET AL 3,168,384

MATERIAL COOLING APPARATUS Filed Feb. 2, 1962 5 Sheets-Sheet 4 Feb. 2, 1965 v M. .1. GREAVES EI'AL MATERIAL cvoouuc APPARATUS 5 Sheets-Sheet 5 Filed Feb. 2, 1962 INVENTOR5 Mil, VM/ 5/, EFF/1V5! nr-rai/vif United States Patent 3,168,384 MATERIAL COOLING APPARATUS Melvin J. Greaves, Cleveland, Tage Werner, Rocky River,

and Robert Eugene Touzalin, Aurora, Ohio, assignors,

by mesne assignments, to Kaiser Steel Corporation,

Oakland, Calif., a corporation of Nevada Filed Feb. 2, 1962, Ser. No. 170,664 11 Claims. (Cl. 34-168) This invention relates to an apparatus for cooling heated material. More particularly, it is concerned with providing an apparatus which constitutes an improvement over that disclosed in Patent 2,681,158, issued June 15, 1954, and which comprises a rotating cooling bin designed for cooling materials such as coke, cement clinker, burnt lime and the sinter discharged from sinterimg machines.

As in the case of the apparatus disclosed in Patent 2,681,158, issued June 15, 1954, this invention will be described as one particularly adapted for cooling sinter discharged from a sintering machine, it being understood, however, that within the broader [aspects of the invention it may be used for cooling numerous other materials, some of which have been referred to above.

Accordingly, it is the primary purpose of this invention to provide an improved device for cooling heated material wherein novel means are employed for passing cool ing air through a bin device containing the body or bed of heated material.

This and other purposes of the invention will become more apparent from a review of the following detailed description when taken in conjunction with the appended drawings, wherein:

FIG. 1 is an elevational sectional view With parts re.-

moved of the improved cooling device of the instant invention;

FIG. 2 is a partial plan and partial sectional view of the cooling device shown in FIG. 1 when generally taken along the line 22 thereof;

FIG. 3 is a sectional view of the cooling device shown in FIG. 1 when taken along the line 33 thereof;

FIG. 4 is an enlarged sectional View of a portion of the cooling device of FIG. 1;

FIG. 5 is a sectional view taken along line 55 of FIG. 4;

1 FIG. 6 is a further enlarged sectional view with parts thereof being shown schematically of a portion of the cooling device of FIG. 1 and discloses a further embodi- The lower inner extremity of each segment A is joined to a central casting or hearing member D mounted on a suitable masonry base E.

The cooling device is rotated by a plurality of drive Wheels F located below the framework 5. Each segment A is comprised of a horizontal floor I-beam ltl affixed to and extending radially outward from the central hub or casting member 12. Casting member 12 is affixed to a shaft or bearing assembly 14 with the bearing assembly then being suitably mounted in the base element E.

Associated with each floor beam are a plurality of diagonal braces or beams 16, 17 and 18, which are secured "ice to the upper flanges or faces of the floor beams. These braces in turn support a horizontal arm 20 of generally I-beam configuration. The outer bracing beam 18 also acts as a support for an extension 22 for each of the arms 20. The inner extremities of horizontal arms 20 have their upper and lower flanges or faces bolted to the circular plates 24 and 25, respectively. These plates are held together by a suitable locking pin 26.

An annular partition or wall of plate steel 28 is secured to the upper faces or flanges of diagonal bracing beams 18 and this wall extends upwardly therealong from the base of the beams 18 to a conical covering 29 also made of steel plate. Covering 29 forms a continuation of wall 28 and it is mounted upon the super structure 5' of the framework 5. Super structure 5' is comprised of the diagonally arranged frame elements 30, the vertical frame elements 31 and the horizontal frame elements 31. Frame elements 30 and 31 are aflixed to the horizontal arms or upper beams 20 in each of the spoke-like segments, making up the framework 5 and frame elements 31 are secured to frame elements 31.

Partition 28 in effect forms an inner retaining wall for the bin structure C and extends in a downwardly and outwardly direction. The portions of the floor beams 10 projecting outwardly beyond bracing members 18 are likewise covered by steel plate to form an annular and substantially horizontal material-receiving shelf 32. Cross beams 34 can be placed between the floor beams 10 to further strengthen the frame assembly 5 at its outer periphery.

Another circular partition 36 of plate steel is secured to the upper faces or flanges of the diagonally arranged arms 38 dependingly aflixed to the outer extremities of the arms 20. Partition 36 extends downwardly and inwardly from one end of an arm 38 to the other. Partition or wall 36 serves as an inwardly inclined outer retaining wall which together with the horizontal shelf 32 and the outwardly inclined inner retaining wall 28 form the annular cooling bin structure or assembly C along the outer periphery of the bin framework 5. Bin structure C can be considered as having a substantially inverted conical cr0sssectional configuration.

By inclining the outer retaining wall 36 inwardly as well as the inner retaining wall 28 outwardly, the flow of sinter material onto the shelf 32 is greatly facilitated. After the material has been cooled, it is ultimately removed from the shelf and onto a conveyor by conventional plow elements'38 and 39 as shown in FIG. 3. Since these plow elements do not fonm any part of the instant invention, a detailed description of the same is not believed required. The horizontal shelf 32, as well as the inclined walls or partitions 28 and 36, may be lined with a suitable refractory firebrick material M laid thereon in a suitable manner. In the case of shelf 32 the firebricks would extend generally from the base of inner retaining wall or partition 28 to the outer edge of the shelf 32.

Because of the sharp inclination of the inner wall 28 and outer wall 36, the accumulation of any great quantity of hot sinter along either wall is effectively prevented. The angle of inclination of both walls 28 and 36 is substantially the same in order to effect a more even flow of the hot sinter material from the top of the bin structure to shelf 32. As a result, the cooling sinter will become more evenly distributed upon the shelf whence it is then removed by the plows 38 and 39.

It will be further'noted by reference particularly to FIGS. 3 and 4 that the outer extremities of the arms 20 are covered by channel-shaped wearing sleeves or jackets 40. Each sleeve 40 is advantageously formed of cast iron or other wear-resistant material. As indicated particularly in FIG. 5, the sleeve 40 combines with the interior structural framework G comprised of conventional horizontally and vertically disposed channel members and I-beams. The enclosing hood 45 is generally of conical shape and it is provided with an outer passageway or duct 46 and inner passageway or duct '47, ducts 46 and 47 being concentrically located with respect to one another. Duct 46 is formed by means of thehood segments 48, 49 and 49'. Segments 48 and 49' in eifect form superimposed cones, while segment 49 forms an outer peripheral wall overlapping the upper part of the bin structure C. The interior wall of duct 46 is made up of the conical wall section 29 mounted on the cooling device, the inner hood segment 50, the wall 51 of the interior duct 47 and the bell-shaped exhaust mouth 101 of duct 47.

The enclosing hood 45 is sealed to the rotating bin structure C by virtue of the liquid sealing means 52 located between the vertically disposed wall 49 of the enclosing hood and the rotating bin structure C, as well as the liquid seal means 53 located between the hood segment 50 and the wall covering 29 aflixed to super structure 5' of the cooling device.

Liquid seal means 52 generally comprises an annular and channel-shaped trough 55 suitably afiixed by gusset plates 49" or the like to the hood or wall segment 49 and to the structural framework G by suitable means (not shown). The lower extremity of hood segment 49 projects into trough 55. It combines with a secondary annular wall 56 anchored to depending arms 38 to form an annular capillary tube-like structure within the trough 55 and in turn provides an adequate liquid seal between the hood 45 and the bin structure C adjacent the upper open top portion thereof. A cooling liquid, such as water or the like, can be continuously passed through the trough '55 through the medium of the feed or inlet pipe 60 and the outlet pipe 61, the cooling liquid being introduced into intake pipe 60 from a suitable source (not shown) while being removed by pipe 61 leading back to this source of supply.

Liquid seal means 53 also comprises an annular and channel-shaped trough 65 afiixed to the upper'portion of the structural frame elements 31 and to frame elements 31' of the super structure of the rotating cooling device. Disposed within the trough 65 is an annulus 66 afiixed to the frame elements of the rotating bin structure and another annulus 67 affixed to the inner hood segment 50. Annuli 66 and '67 combine to form a capillary-like structure 68, intermediate hood segment 50 and the covering or deck 29 of the rotating bin whereby an effective liquid seal is provided between the interior portion of the hood structure and the rotating bin structure. A cooling liquid, such as water, can be continuously fed to the'trough 65 by means of the intake pipe 70. An overflow pipe 71 discharges the water into the annular collection basin 71' located at the base E for the rotating bin structure. The water in basin 71' can be continuously returned by means of the drain'or return pipe 72 to the main source of supply for the liquid seals where it is then cooled prior to its return to the cooling device. Drain pipes 73 provided with suitable extensions 74 and 75 connected to the bottom portion of trough 65 are used to evacuate or empty trough 65, whenever desired, by opening valves 76 and 77 in lines 74 and 75. The outer annular wall 74' of trough 65 is afiixed to the vertical frame elements 31, while the inner annular wall 75' which provides an opening connecting duct 47 with the interior framework .of the cooling device is mounted on frame elements 31'.

:In a further advantageous embodiment of the invention it will be observed by reference particularly to FIGS.

4 and 5 that means are provided for cooling the outer hollow extremities 22 of the arms 20 located at the top a of the bin structure C or the extremities of the arms 20 which are subjected directly to the action of the sinter material passing into the bin structure C. Extremities 22 along with sleeves 40 also serve as hollow bridging elements between the walls 28 and 36 of the bin structure C. These means generally comprise an intake pipe 80 leading from the liquid seal trough 65 to the cooling chamber 42' of the arm 20. Cooling chamber 42' is in open communication with the other cooling chamber 41' of arm 29 by virtue of the outlets 82. Cooling fluid passes from chamber 42' into the chamber 41" whence it then passes through the conduit 82' and into collection basin 71. Located in piping or conduit 82 is a metering valve 83 which is used to regulate the flow of cooling fluid to and from the outer extremity 22 of an arm 20.

In some instances, depending upon the material being cooled, it may be desirable to direct a cooling fluid directly upon the material located in the bin structure C. One arrangement for doing this is to connect a spray pipe 85 aflixed to and located at a predetermined point within hood 45 to a conduit or piping 86 whichin turn is connected to a suitable source of supply. A metering valve 87 can be likewise afiixed to the piping 86 in order to regulate the flow of cooling fluid through the spray pipe 85 and out through the openings 90 therein, openings 90 being located over the bin structure C.

It will be further observed, reference being made particularly to FIGS. 6 and 7 of the drawings, that material such as sinter is advantageously discharged into the top of bin structure C through the medium of a vibrating screen device 120. A dust and fines collection trough or the like is located below the screen device 120. The screen device 120 empties into a chute 121, which projects into the inner chamber or tower 122 formed by portions of the wall segments 48 and 49 of the hood 45, side walls 123, 124 and 125 and the inclined bottom walls 123', 12 4', 125' and 126. Tower 122 has a bottom opening 127 for discharging material into receiving and cooling bin C. The lower extremities of walls 123 and 125 are advantageously provided with metal flaps 130 pivotally attached thereto, the bottoms of the flaps 130 being located slightly above the normal level of the material in the bin C. Due to the pivotal attachment of the flaps 130 to walls123 and 125, these flaps will not interfere with the rotation of the bin C if for any reason an excess of sinter material is discharged into the bin C. Drag chains 131 can also be located on the inside and outside of the flaps to assist in holding them in a true vertical position. The purpose of these flaps 130 is to help seal off chamber or tower 122 from the outer duct system 46 as much as is practicable and confine as much dust and fines as possible within chamber or tower 122. It has been found that approximately 90 percent of the dust and fines that occur as a normal incident to the use of the cooling device accrue at the point of discharge of the sinter material into the cooling bin C. Accordingly, most eflicient operation of the cooling device will be effected if the major portion of the dusts and fines resulting from discharge of the sinter material into thecooling bin are collected at this point of discharge. Chamber or tower 122 can therefore be considered as a dust and fine collection chamber or tower.

The upper part of tower 122 is connected by means of the stack 135 to a centrifugal induced draft fan sep arating device 136 of conventional design. The dust, 'etc., is withdrawn from tower 122 and through stack 135 into the centrifugal dust separation device 136 where it then is passed to a suitable dust and fine collection apparatus. An air seal 137 which can be a pivotally mounted door or the like is located above chute 121. Air seal 137 ensures the passage of air through bin C adjacent to and below tower 122 through opening 127 and chamber 122 and out opening 122' at the top thereof along with the dust, etc., in chamber 122 and then through duct 135 and into the centrifugal dust collecting device 136. For all practical purposes, the separate passage of air through tower 122, etc., does not interfere with the normal passage of cooling atmospheric air through the major portion of bin C and into the outer duct system 46. It is to be realized that although a small amount of air may by-pass opening 127 and escape through the opening 140 between walls 124 and 124' and decking 28 and 29, this by-passage of air has no serious effect on the dust collecting operation performed in chamber 122.

The inner duct wall 51 of the hood enclosure 45 can be held in place and secured to the outer hood segment 49 by means of a spider-like framework 100. Bell mouth exhaust 101 for duct 47 is in open communication with an exhaust stack 102. The outer conduit 46 of hood 45 is cut off from direct communication with exhaust stack 102 by virtue of this bell mouth 101 which is sealed to the exhaust stack 102. Outer conduit 46 of the hood structure, however, is provided with openings or ports 105 at the top thereof and adjacent the exhaust stack 102. These openings 105 are advantageously located in pairs and although three such pairs of openings 105 are shown any number can be employed depending upon the results desired. Openings 105 serve as intake ports for the blowers or exhaust fans 107. The intake sides of fans 107 are connected to the ports 105 by ductwork 106. Although three such fans are shown in the drawings, it is to be understood that any number of fans can be employed depending upon the results desired. The exhaust side of each of the fans 107 is in open communication with a duct 108. Each duct 108 communicates with the main exhaust stack 102 through the medium of an opening 109. Interior duct 47 of hood 45 is in open communication with exhaust stack 102 through the medium of bell mouth 101 and with the open interior framework of the cooling device through the medium of the inner hood segment 50 which also has the shape of a bell mouth.

From the above description it will now be observed that cooling atmospheric air is positively drawn by means of fans 107 across the material being cooled in the bin C even during discharge of sinter into bin C. As the air is drawn upward by fans 107 it passes through the outer conduit or duct 46, through openings 105, ducts 106 and the blowers 107 whence it is then expelled in a heated condition by means of the blowers 107 through the exhaust ducts 108 and openings 100 into the main exhaust stack 102. Air is simultaneously drawn through the open framework forming the interior of the rotating bin structure through the opening provided by wall 75' of trough 65 and into interior conduit or duct 47. The air then passes out through bell month 101 and into the main exhaust stack 102. The air passing upwardly through the interior framework of the rotating cooling device also assists in the cooling of material disposed in bin structure C by virtue of radiation of the heat from the material in the bin C through wall or decking 28.

By virtue of the above arrangement as described, means are provided for positively drawing cooling atmospheric air through and across the material to be cooled. This in turn efiectively decreases the cooling time for a given amount of material deposited in bin C, while at the same time indirectly increasing its cooling capacity. Blowers 107 serve a further useful purpose in that they help to remove any dust and fines in the material being cooled and which may have escaped from tower 122 by drawing them out through the exhaust stack 102 simultaneously with cooling the material in bin C. In any event, by removing the dust and fines primarily through tower 122 undue wear on the main fans 107 is avoided and dust collection equipment and fan horsepower sufficient to clean a small portion of the cooling air 'is normally required. At the same time, the liquid sealing means 52 and 53 effectively seal the fixed enclosing hood 45 to the rotating bin structure and prevent short circuiting of the cooling air as it passes over the material being treated in bin C.

An advantageous embodiment of the invention has been disclosed and described. It is obvious that various changes and modifications may be made therein without departing from the spirit and scope thereof as defined in the appended claims, wherein what is claimed is:

1. In a cooling device of the character described the combination of a rotatable bin structure provided with an annular downwardly and outwardly inclined inner wall and an annular downwardly and inwardly inclined outer wall, said outer wall being of a shorter length than said inner wall, a substantially horizontal shelf extending outwardly from the base of the inner wall and beyond the lower extremity of said outer wall, said shelf also being open to the atmosphere, means for supporting and rotating said bin structure, a hood comprised of inner and outer segments enclosing the top portion of said bin structure and provided with exhaust conduit means, means for drawing cooling atmospheric air into said bin structure and into contact with the material disposed in said bin structure and for exhausting said air through said exhaust conduit means, a first sealing means sealing the inner segment of said hood with the annular downwardly and outwardly inclined inner wall of the bin structure, and another sealing means sealing the outer segment of said hood with said annular downwardly vand inwardly inclined outer wall of said bin structure so as to insure the passage of cooling atmospheric air into and through the bin structure and the exhausting of said through said exhaust conduit means.

2. In a cooling device of the character described the combination of a rotatable bin structure provided with an annular downwardly and outwardly inclined inner wall and an annular downwardly and inwardly inclined outer wall, said outer wall being of a shorter length than said inner wall, a substantially horizontal shelf extending outwardly vfrom the base of .the inner wall and beyond the lower extremity of said outer wall, said shelf also being open to the atmosphere, mean-s ior supporting and rotating said bin structure, hood means enclosing the top portion of said bin structure and provided with exhaust conduit means, means for drawing cooling atmospheric air into said bin structure and into contact with the material disposed in said bin structure and for exhausting said air through said exhaust conduit means and liquid seal means sealing said hood means to the rotatable bin structure.

3. A cooling device as set forth in claim 2 including hollow bridging elements joining the inner and outer walls of said bin structure together and means connecting the interior of said hollow bridging elements with said liquid seal means.

4. In a cooling device for cooling sinter material and the like, the combination of :a rotating bin structure provided with an annular downwardly and outwardly inclined inner wall and an annular downwardly and inwardly inclined outer wall, said outer wall being of a shorter length than said inner wall, a substantially horizontal shelf extending outwardly from the base of the inner wall and beyond the lower extremity of said outer wall, means for supporting and rotating said bin structure, hollow bridging elements joining said inner and outer walls of said bin structure together, hood means enclosing the top portion of said bin structure, liquid seal means sealing said hood means to the top of said rotating bin structure and means connecting the interior of said hollow bridging elements with said liquid seal means and for passing liquid from said liquid seal means through said hollow bridging elements so as to cool the same.

5. In combination with a rotatable annular bin structure which is open at the top and bottom thereof and which is provided with an inner wall, an outer wall and a mate- 7 rial-receiving shelf at the bottom thereof, a hood means sealed to the top of said bin structure, said hood means comprising a plurality of concentrically arnanged conduits,

an exhaust stack, an exhaust fan means connected directly to one of said concentrically arranged conduits and to said exhaust stack, said fan means being operable to draw cooling air through the open bottom of the bin structure and into contact with the material deposited in said bin structure and through said one of saidconduits and then into said exhaust stack and said hood means including an inner hood segmentsealed to said inner wall of said bin structure and an outer segment sealed to the, outer wall of said bin structure so as'to insure the passage of said cooling air through the open bottom of said bin structure and into contact with the material deposited in said bin structure and then through said one of said conduits and into said exhaust stack.

6. In combination with a rotatable annular bin structure which is open at the top andbottornthereof and which is provided with a materiahreceiving shelf at the bottom thereof, a hood means sealed to the top of said bin structure, saidhood means comprising a plurality of concentrically arnanged conduits, an exhaust stack, an exhaust fan means connected directly to one of said concentrically arranged conduits and to said exhaust stack,

and an annular downwardly and inwardly inclined outer wall, .said outer wall being of ash-orter length than said innerwall, a substantially horizontal shelf extending outwardly from the base of'the inner wall and beyond the lower extremity of said outer wall, said shelf also being open to the atmosphere, means for supporting and rotating said bin structure, hood means enclosing the top portion of said bin structure and provided with exhaust conduit means, said hood means including inner and outer segments, the inner segment of said hood means being sealed to said inner wall of the bin structure and said outer segment being sealed to the outer wall of said bin structure; means for drawing cooling atmospheric into and through said bin structure and into contact with the mate: rial disposed in said bin structure and for exhausting said air thnoughsaid exhaust conduit means, a dust collecting tower disposed within said hood means and above said bin 9 and adjacent the point of bin entry of the material to be said fan means being operable to dnaw cooling air through I the open bottom of the bin structure and into contact with the material deposited in said bin structure and through said one of said conduits and then into said exhaust stack, and liquid seals sealing said hood means to said bin structure.

ture which is open at the bottom and top thereof and which is provided with a material-receiving shelf at the bottom thereof, a hood means sealed to the top of said bin structure, said hood means comprising a plurality of concentrically arranged conduits, an exhaust stack, an exhaust fan means connected directly to one of said concentrically arranged conduits and to said exhaust stack, said fan means being operable to draw cooling air through the open bottom of the bin structure and into contact the material deposited in said bin structure and through said one of said conduits and then into said exhaust stack, and liquid seal means sealing said hood means to said bin structure and said bin structure including converging Spaced vwalls having hollow bridging elements therebetween and means connecting said hollow bridging elements to said liquid seal means. I,

8. In a cooling apparatus of the'type described the combination of a rotatable bin structure open at the bottom and top and provided with inner and outer spaced walls and a material-receiving shelf, afixed hood means sealed to the top of said bin structure, said hood means being provided with a plurality of concentrically arranged conduits and an exhaust stack means, one of said conduits being in open communication :with the top of said bin structure and the other of said conduits being in open communication with said exhaust stack means, an exhaust fan means, a duct means connecting the intake side of the fan means with said one of said conduits and a second duct means connecting the exhaust side of the fan means to said exhaust stack means.

9. In a cooling device of the character described the combination of a rotatable bin structure provided with an annular downwardly and outwardly inclined inner wall 7. In combination with a rotatable annular bin strucwall, said outer wall being of a shorter length than said inner wall, a substantially horizontal 'shelf extending outwardly from the base of the inner wall and beyond the lower extremity of's'aid outer wall, said shelf also being open to the atmosphere, means for supporting and rotating said bin structure, hood means enclosing the top portion of said bin structure and provided with exhaust conduit means, means for drawing cooling atmospheric air into and through said bin structure and into contact with material disposed in said bin structure and for exhausting said air through said exhaust conduit means, a dust-collecting tower disposed within said hood means and above said bin structure and adjacent the point of bin entry of the material to be cooled by said cooling device, exhaust fan means for withdrawing dust from said tower and liquid sea-l means sealing said hood means to said rotatable bin structure. 7 a

11. In combination with a rotatable annular binstructure which, is open at the top and. bottom thereof and which is provided with a material-receiving shelf at the bottom thereof, a hood means sealed to the top of said bin structure, said hood means comprising a plurality of concentrically arranged conduits, an exhaust stack, an exhaust fan means connected directly to one of said concentrically larnanged conduits and to said exhaust stack, said fan means being operable to draw cooling air through the open bottom of the bin structure and into contact with the material deposited in said bin structure (and through said one'of, said conduits and then into said exhaust stack and a dust collect-ion tower disposed within said hood means and above said binand exhaust fan means for withdrawing dust from said tower.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A COOLING DEVICE OF THE CHARACTER DESCRIBED THE COMBINATION OF A ROTATABLE BIN STRUCTURE PROVIDED WITH AN ANNULAR DOWNWARDLY AND OUTWARDLY INCLINED INNER WALL AND AN ANNULAR DOWNWARDLY AND INWARDLY INCLINED OUTER WALL, SAID OUTER WALL BEING OF A SHORTER LENGTH THAN SAID INNER WALL, A SUBSTNATIALLY HORIZONTAL SHELF EXTENDING OUTWARDLY FROM THE BASE OF THE INNER WALL AND BEYOND THE LOWER EXTREMITY OF SAID OUTER WALL, SAID SHELF ALSO BEING OPEN TO THE ATMOSPHERE, MEANS FOR SUPPORTING AND ROTATING SAID BIN STRUCTURE, A HOOD COMPRISED OF INNER AND OUTER SEGMENTS ENCLOSING THE TOP PORTION OF SAID BIN STRUCTURE AND PROVIDED WITH EXHAUST CONDUIT MEANS, MEANS FOR DRAWING COOLING ATMOSPHERE AIR INTO SAID BIN STRUCTURE AND INTO CONTACT WITH THE MATERIAL DISPOSED IN SAID BIN STRUCTURE AND FOR EXHAUSTING SAID AIR THROUGH SAID EXHAUST CONDUIT MEANS, A FIRST SEALING MEANS SEALING THE INNER SEGMENT OF SAID HOOD WITH THE ANNULAR DOWNWARDLY AND OUTWARDLY INCLINED INNER WALL OF THE BIN STRUCTURE, AND ANOTHER SEALING MEANS SEALING THE OUTER SEGMENT OF SAID HOOD WITH SAID ANNULAR DOWNWARDLY AND INWARDLY INCLINED OUTER WALL OF SAID BIN STRUCTURE SO AS TO INSURE THE PASSAGE OF COOLING ATMOSPHERIC AIR INTO AND THROUGH THE BIN STRUCTURE AND THE EXHAUSTING OF SAID AIR THROUGH SAID EXHAUST CONDUIT MEANS. 